You might want to give the private mini storage on the north side of 290 between Jones Rd. and Eldridge/West Rd. a try. I used to keep my boat there. It has a nice in and out access, wash down area, but enclosed spaces are limited though...Worth a shot........MZ
Affordable storage -- it's on 529 west of Barker Cypress on the left. There is also one mentioned above on 529 between Queenston and Hwy 6 -- from Queenston/529 that is left and it's on the left then ... near Wal Mart on 529.
Welcome to NW Houston... if you need a fishing partner from out that way... drop me a line.